The LiPo was my thought as well...
Yet I am not sure I really want to run light off the main battery: in case of unexpected landing (e.g. due to empty battery) the lights won't be able to help you with recovery - if they run on seperate power, they will still be on, even if the battery flew out in a severe crash.
You don't even need a lipo. Depends how bright you want them. Buy a cheap small pocket torch. Break it apart... Done.
Whatever you put on it tho could fly off. Add weight will reduce flight time. Guess it's personal preference.
I think all these things (lights, LEDs, flashing lights, etc.) are useless on Tello! just an extra weight and ruin the aesthetics of the drone not to mention the overheating if we cover the air intake.
I only say what I think, then everyone is free to do what he wants!
For Louis08 To prevent the battery from being disconnected in the event of an accident, there is an accessory suitable for this purpose.
Of course it is all about personal preference, so I wouldn't call it completely useless . It's a bit like pimping your car with flashy accessories....
Putting position lights on a Tello is (at least for me ) more a matter of being able to do it without screwing up the whole rig than achieving a real benefit.
BTT: Weight is of course an issue - or a challenge. Without using a seperate battery it should easily be possible to end up below 10g for the whole light set. And even adding a small battery (e.g. 150mAh LiPo from Adafruit) should still be possible; it adds ~5g but would save you the USB plug.
There's another thread here about weight influencing flight time: an extra 20g (~22% of takeoff weight) reduced hovering time by 12%.
In any case I'd rather modify the top cover than covering the air intake below; spare covers are rather cheap when you buy in China (even original Ryze ones).
Would anybody eventually know off the top of their head whether the USB port delivers 3.7V or 5V?